This invention relates to mining machines of the kind which are used to cut a variety of soft materials such as coal.
In machines of this type a plurality of cutting tools (also known as elements) are positioned, for example, on the surface of a drum, in a cutting direction against the face of the material to be cut. Each tool comprises a holding lug and an insert usually secured in a socket in the lug. The cutting tip of the insert may be made of cemented carbide or abrasive compact.
The insert is usually secured to the bore of the lug by means of a braze. During brazing, it is necessary to heat the zone of the lug surrounding the bore. The lug is normally made of a hardened steel and this heating causes the hardened steel in this zone and elsewhere to soften. Thus, brazing does have the disadvantage that it introduces a weakness into the cutting tool.